Intake backfire going into boost.

[solowma]

I put a rough tune into the truck a couple of weeks ago. It started up right and runs great at idle. My friend and I adjusted the timing and got everything dialed in.
When driving and I role into the throttle the truck goes fine into boost from vacumm. AFR is fine and then gets rich up towards 6 to 7psi of boost. That will be solved later.
Now the problem is, when you snap the throttle for a hard accelleration, it backfires into the intake plenum. Now I do have the 2114 conversion on my truck (see sig)
It goes extremely lean when it hits atmosphere pressure. Any suggestions what might be causing this?
And another question is why does the VE table for map only goe to 105 kpa? Boosted application should have higher than that right?

[PartsGuy]

They do, but that PCM is not designed for that. If you still have the MAF it shouldn't make a diff anyway.

[solowma]

I still have the maf and I guess I will have to adjust the maf table to get it to respond better and not backfire

[PartsGuy]

Sounds to me like it may be getting lean before your FMU can pick up the slack for the enrichment. I know the standard Procharger one starts to enrich at about 3 psi so you have a breif period of no help.You might be able to fine tune it with a combination of MAF table and PE table around that RPM and airflow point. Let us know how it goes.

[solowma]

It just seems that it backfires when you step on it between shifting or I am in a gear an snap the throttle. I had an fmu before that was responsive to a .25 psi. This Aeromotive fuel pressure regulator may not react quick enough. Besides, I switched over to a multiport system and should be able to tune the truck for this exact problem. I just don't know where too.

[PartsGuy]

I would like to look at your file but your vdf is one of the few I don't have.

[PartsGuy]

What vdf do you use? Do you have the black, 4 connector style PCM?

[solowma]

Yes the pcm is the 4 connector style. Do you still want the file?